package com.hmdp.utils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;



    private static final long BEGIN_TIMESTAMP = 1640995200L;

    //    定义一个序列号位数
    private static final long COUNT_BITS = 32;

    public long nextId(String keyPrefix) {
        //    生成时间戳
        LocalDateTime now = LocalDateTime.now();
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy:MM:dd");
//        注意 localDateTime不能用SimpleDateFormat
        String date = now.format(dateTimeFormatter);
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //    生成序列号
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //  拼接并返回

        return timestamp <<COUNT_BITS|count;
    }


}
